Chet Baker, Keith Jarrett, and Pat Metheny.
(This remains a mystery, except perhaps when you think of the existence of the Europop Festival)
...and some great musicians that most of them don't know about:
Johnny Griffin
Art Pepper
Lennie Tristano
Lester Bowie
Roland Kirk
Gigi Gryce
They also tend to overrate Oscar Peterson a bit, but I guess there's no helping that. The guy sounds the way you imagine jazz ought to sound if you haven't listened to a lot of jazz. He's just a little too correct and straight-ahead to offer a visionary breakthrough. A virtuoso, but a template.
So spread the word and make some friends.
Oh and they love Bill Evans, which is fine -- but usually the wrong Bill Evans. Turn them on to the earlier stuff, like Sunday at the Village Vanguard, before Scottie LaFaro died.
